IOTA/IOTA-ES occultation update for (773) Irmintraud / 2UCAC 12320874 event on 2008 May 14, 22:20 UT Visible from Africa Summary ------- On 2008 May 14 UT, the 96 km diameter asteroid (773) Irmintraud will occult a 12.0 mag star in the constellation Ara for observers along a path across Africa. In the case of an occultation, the combined light of the asteroid and the star will drop by 1.7 mag to 13.4 mag (the magnitude of the asteroid) for at most 16.3 seconds. This update is based on UNSO/Flagstaff astrometry for the asteroid kindly provided by Alice Monet, historical astrometry from the MPC files (via AstDys), and the following catalogs for the star position: UCAC. The event at a glimpse ---------------------- * Rank: 96 * date and approx. time of event: 2008 May 14, 22:12 - 2008 May 14, 22:29 UT * magnitude of target star: 12.0 * magnitude drop [mag]: 1.7 * estimated maximum duration [s]: 16.3 * Moon: 76 % sunlit, 94° distance * Sun: 138° distance * rough path description: Africa The occultation path -------------------- * approximate projected width [km]: 200 * 1 sigma uncertainty interval [path widths]: +/- 0.41 * 1 sigma uncertainty interval [seconds]: +/- 7.5 * 1 sigma uncertainty interval approx RA,DE ["]: (+/- .044 +/- .029) * 1 sigma uncertainty ellipse (major, minor, PA): ( .045", .029", 79° ) * approx speed of asteroid's shadow [km/s]: 5.8986 * website for maps: http://www.asteroidoccultation.com Path Coordinates: Occultation of 2UCAC 12320874 by 773 Irmintraud on 2008 May 14 Centre Star Star Sun Path Limits Error Limits E. Longitude Latitude U.T. Alt Az Alt Limit 1 Limit 2 Limit 3 Limit 4 o ' " o ' " h m s o o o o ' " o ' " o ' " o ' " Longitude Longitude Longitude Longitude 61 51 9 44 0 0 22 12 7 0 177 -19 60 30 55 63 9 1 59 23 9 ... .. .. 61 53 34 43 0 0 22 12 8 1 177 -20 60 34 40 63 10 9 59 28 6 ... .. .. 61 53 8 42 0 0 22 12 9 2 177 -21 60 35 27 63 8 36 59 29 55 ... .. .. 61 50 0 41 0 0 22 12 11 3 177 -22 60 33 23 63 4 28 59 28 46 ... .. .. 61 44 16 40 0 0 22 12 13 4 177 -22 60 28 34 62 57 50 59 24 45 ... .. .. 61 36 0 39 0 0 22 12 16 5 177 -23 60 21 7 62 48 49 59 18 0 63 47 6 61 25 18 38 0 0 22 12 20 6 177 -24 60 11 6 62 37 27 59 8 34 63 35 13 61 12 13 37 0 0 22 12 25 7 177 -25 59 58 35 62 23 48 58 56 33 63 21 7 60 56 47 36 0 0 22 12 30 8 176 -26 59 43 38 62 7 55 58 41 59 63 4 52 60 39 3 35 0 0 22 12 36 9 176 -27 59 26 15 61 49 50 58 24 54 62 46 29 60 19 2 34 0 0 22 12 43 10 176 -28 59 6 29 61 29 33 58 5 20 62 25 59 59 56 44 33 0 0 22 12 50 11 176 -29 58 44 20 61 7 5 57 43 18 62 3 22 59 32 9 32 0 0 22 12 59 12 175 -30 58 19 48 60 42 26 57 18 46 61 38 39 59 5 16 31 0 0 22 13 8 13 175 -31 57 52 51 60 15 35 56 51 44 61 11 48 58 36 3 30 0 0 22 13 18 14 175 -32 57 23 28 59 46 30 56 22 10 60 42 49 58 4 28 29 0 0 22 13 28 15 174 -33 56 51 35 59 15 10 55 50 0 60 11 38 57 30 28 28 0 0 22 13 40 16 174 -34 56 17 9 58 41 31 55 15 10 59 38 15 56 53 58 27 0 0 22 13 52 17 174 -35 55 40 6 58 5 30 54 37 35 59 2 34 56 14 53 26 0 0 22 14 5 18 173 -36 55 0 18 57 27 1 53 57 7 58 24 31 55 33 6 25 0 0 22 14 19 19 173 -37 54 17 39 56 45 59 53 13 39 57 44 2 54 48 29 24 0 0 22 14 34 20 172 -39 53 31 59 56 2 16 52 27 0 57 0 59 54 0 52 23 0 0 22 14 51 21 172 -40 52 43 7 55 15 45 51 36 57 56 15 15 53 10 4 22 0 0 22 15 8 21 171 -41 51 50 50 54 26 15 50 43 16 55 26 41 52 15 50 21 0 0 22 15 26 22 170 -42 50 54 50 53 33 33 49 45 36 54 35 5 51 17 54 20 0 0 22 15 46 23 170 -44 49 54 48 52 37 25 48 43 35 53 40 15 50 15 54 19 0 0 22 16 7 24 169 -45 48 50 19 51 37 32 47 36 42 52 41 54 49 9 24 18 0 0 22 16 29 25 168 -46 47 40 49 50 33 34 46 24 19 51 39 44 47 57 50 17 0 0 22 16 53 25 167 -48 46 25 39 49 25 1 45 5 36 50 33 19 46 40 30 16 0 0 22 17 19 26 166 -49 45 3 53 48 11 20 43 39 25 49 22 12 45 16 27 15 0 0 22 17 47 27 165 -51 43 34 18 46 51 46 42 4 11 48 5 43 43 44 25 14 0 0 22 18 17 27 164 -52 41 55 9 45 25 19 40 17 32 46 43 4 42 2 33 13 0 0 22 18 50 28 163 -54 40 3 48 43 50 40 38 15 44 45 13 10 40 8 6 12 0 0 22 19 27 28 161 -55 37 55 59 42 5 52 35 52 2 43 34 32 37 56 32 11 0 0 22 20 9 29 160 -57 35 23 45 40 7 58 32 51 46 41 44 58 Latitude Latitude Latitude Latitude 36 0 0 10 14 21 22 20 45 29 158 -59 11 13 12 9 17 24 12 3 2 8 32 0 35 0 0 9 53 28 22 21 3 29 157 -59 10 51 42 8 57 4 11 40 59 8 12 5 34 0 0 9 34 18 22 21 21 29 157 -60 10 32 0 8 38 24 11 20 47 7 53 47 33 0 0 9 16 49 22 21 39 28 156 -60 10 14 2 8 21 21 11 2 23 7 37 4 32 0 0 9 0 59 22 21 57 28 155 -61 9 57 46 8 5 55 10 45 45 7 21 56 31 0 0 8 46 47 22 22 15 28 155 -61 9 43 12 7 52 4 10 30 50 7 8 20 30 0 0 8 34 11 22 22 32 28 154 -62 9 30 17 7 39 45 10 17 37 6 56 15 29 0 0 8 23 10 22 22 49 28 154 -62 9 18 59 7 28 59 10 6 5 6 45 40 28 0 0 8 13 43 22 23 6 27 153 -63 9 9 18 7 19 44 9 56 12 6 36 35 27 0 0 8 5 49 22 23 23 27 152 -63 9 1 13 7 12 0 9 47 58 6 28 58 26 0 0 7 59 27 22 23 40 27 152 -63 8 54 44 7 5 46 9 41 21 6 22 50 25 0 0 7 54 38 22 23 56 26 151 -63 8 49 48 7 1 2 9 36 21 6 18 9 24 0 0 7 51 20 22 24 12 26 151 -63 8 46 28 6 57 46 9 32 57 6 14 56 23 0 0 7 49 34 22 24 28 26 150 -63 8 44 41 6 56 1 9 31 11 6 13 10 22 0 0 7 49 20 22 24 44 25 150 -63 8 44 29 6 55 44 9 31 1 6 12 52 21 0 0 7 50 37 22 24 59 25 149 -63 8 45 52 6 56 58 9 32 28 6 14 2 20 0 0 7 53 28 22 25 14 24 149 -63 8 48 50 6 59 41 9 35 32 6 16 40 19 0 0 7 57 51 22 25 29 24 148 -63 8 53 24 7 3 55 9 40 15 6 20 47 18 0 0 8 3 49 22 25 43 23 148 -63 8 59 34 7 9 41 9 46 38 6 26 24 17 0 0 8 11 21 22 25 58 22 147 -62 9 7 23 7 16 59 9 54 41 6 33 31 16 0 0 8 20 30 22 26 12 22 147 -62 9 16 51 7 25 50 10 4 25 6 42 9 15 0 0 8 31 17 22 26 25 21 147 -62 9 28 0 7 36 17 10 15 54 6 52 21 14 0 0 8 43 43 22 26 39 20 146 -61 9 40 51 7 48 20 10 29 8 7 4 6 13 0 0 8 57 51 22 26 52 20 146 -61 9 55 27 8 2 1 10 44 11 7 17 28 12 0 0 9 13 42 22 27 4 19 145 -60 10 11 51 8 17 23 11 1 4 7 32 27 11 0 0 9 31 19 22 27 17 18 145 -60 10 30 5 8 34 27 11 19 51 7 49 6 10 0 0 9 50 46 22 27 28 17 145 -59 10 50 13 8 53 17 11 40 35 8 7 28 9 0 0 10 12 4 22 27 40 17 144 -58 11 12 17 9 13 54 12 3 21 8 27 35 8 0 0 10 35 19 22 27 51 16 144 -57 11 36 22 9 36 24 12 28 12 8 49 30 7 0 0 11 0 34 22 28 2 15 144 -57 12 2 33 10 0 48 12 55 14 9 13 17 6 0 0 11 27 53 22 28 12 14 143 -56 12 30 55 10 27 11 13 24 33 9 38 59 5 0 0 11 57 23 22 28 21 13 143 -55 13 1 34 10 55 39 13 56 16 10 6 40 4 0 0 12 29 8 22 28 31 12 143 -54 13 34 36 11 26 16 14 30 30 10 36 26 3 0 0 13 3 16 22 28 39 11 143 -53 14 10 11 11 59 8 15 7 24 11 8 22 2 0 0 13 39 55 22 28 47 10 142 -52 14 48 26 12 34 22 15 47 9 11 42 34 1 0 0 14 19 13 22 28 54 9 142 -51 15 29 32 13 12 6 16 29 57 12 19 9 0 0 0 15 1 22 22 29 1 8 142 -50 16 13 42 13 52 29 17 16 2 12 58 15 - 1 0 0 15 46 32 22 29 7 6 141 -49 17 1 11 14 35 41 18 5 43 13 40 1 - 2 0 0 16 34 59 22 29 12 5 141 -48 17 52 16 15 21 54 18 59 20 14 24 38 - 3 0 0 17 27 0 22 29 16 4 141 -46 18 47 18 16 11 22 19 57 21 15 12 17 - 4 0 0 18 22 55 22 29 19 3 140 -45 19 46 45 17 4 22 21 0 18 .. .. .. - 5 0 0 19 23 11 22 29 20 1 140 -44 20 51 10 18 1 14 .. .. .. .. .. .. Uncertainty in time = +/- 10 secs [Prediction of 2008 May 8.0] Data for the target star ------------------------ * name: 2UCAC 12320874 * constellation : Ara * J2000 position with proper motion to date of event [h,m,s ; °,',"] RA: 18 07 50.9364 DE: -45 46 59.941 * position source: mpos:UCAC2 pm:UCAC2 * standard error: RA,DE ["]: ( .023, .023 ) * V mag [mag]: 12.0 * B mag [mag]: 0.0 * remarks: Data for the minor planet ------------------------- * general information: (number) name: (773) Irmintraud approx. diameter [km]: 96 approx. diameter ["]: .072 distance from Earth [AU]: 1.83600 * orbital information: orbit source: Preston date of fit: 2008 May 07 source of used astrometry: FASTT MPC (via Astdys) number of used observations: 663 number of rejected observations: 64 time covered by the observations: 1914 Jan 15 - 2008 Apr 15 1 sigma uncertainty ellipse (major, minor, PA): 0.039, 0.018, 76° remarks: * orbital elements for (773) Irmintraud : Mean anomaly = 326.10800252 deg Arg. of pericenter = 334.02585616 deg Long. of node = 322.45155107 deg Inclination = 16.68281751 deg Eccentricity = 0.08230385 Semimajor axis = 2.85808610 AU Perihelion dist = 2.62285461 AU Mag: H = 9.02, G = 0.15 Epoch of elements : MJD 54600.93100000 TDT (2008 May 14.931) ------ occelmnt file for Occult BEGIN ----------------------------------- 2008 May 14 773 Irmintraud 22h 20.7m UT 12.0 18 7 50.936-45 46 59.942UCAC 12320874 0.0 13.4 96 16.3 1.836 -1.301 -8.34 63.7609 -45.780 -156.08 18.89 22.3450 -0.45857 0.74777 -2.83677 -1.74272 -0.00336 0.00164 2000 325.9180962008 514.00000334.025856322.451551 16.6828180.08230385 2.8580861 2.6228546 9.1 5.00.15 RATE 2.0398170 0.000000 0.000000 0.000000 0.0000000 0.0000000 0.0000000 Meas 0.045 0.029 79 1.41 0.030 0 54594.5020080514_320874 ------ occelmnt file for Occult END ----------------------------------- ============================================ Calculator (s): Steve Preston Date of update: 2008 May 08, 03:15 UT Steve Preston 7640 NE 32nd St Medina, WA 98039 425-688-9965 mailto: stevepr@acm.org